CYCLICITY IN THE CERREJON FORMATION

The Cerrejon Formation exhibits a stacking pattern characteristically repetitive and monotonous. It has a stratigraphic thickness of about 1000 m and a strike- length of at least 30 km through Cesar - Rancheria Valley. This monotony has been used to define eight lithofacies assemblages, and three typical sequences that describe the entire unit. The vertical arrangement of these lithofacies assemblages allows the recognition of stacking patterns, but not the mechanisms that generated the repetition and the vertical arrangement of these patterns. This study aims to identify cyclicity in the record and to establish a possible causal relationship for these patterns. To do this, forward modeling was used and preliminarily indicates that the punctuated progradational pattern observed in the Cerrejon Formation can be simulated keeping constant tectonic subsidence, sedimentation rates, and forcing a base level oscillation. Only tectonic or thermal subsidence, differential compaction or autocyclic phenomena could not easily generate the observed pattern on such regional extension.